For many years there has been a desire to provide, for instance, an autonomous apparatus for floor treatment, particularly a vacuum-cleaner, which is controlled by a sensing system sweeping around the horizon in analogy, for example, with a ship radar. Then the desire is, that the apparatus should be able to orientate itself in a room, such that it, for instance, will be able to perform a cleaning function according to a predetermined pattern or a predetermined strategy and at the same time avoid colliding with different obstacles, which may be arranged in the room, besides avoiding collisions with the walls of the room.
Such a system is disclosed in the International Patent Application WO 95/26512 by the same applicant and which is expressly incorporated here by reference.
Still the system according to WO 95/26512 is rather complicated and it additionally utilizes a number of transponder devices for the initial orientation. These transponders are localized at a number of points in the room to be cleaned and the transponders are used as reference points. Another characteristic of the system according to WO 95/26512 is the utilization of an ultrasound transmitter placed on top of the device. This transmitter is used both for localization of the transponders scattered around the room and is simultaneously used as a proximity sensing system for detecting possible obstacles near to the moving apparatus. One disadvantage of the disclosed apparatus is due to limited bandwidth and therefore there will sometimes be present "dead" sectors.
Therefore there is a desire to find an improved apparatus for automatic polishing or vacuum-cleaning presenting an even better ability to find a clear way when performing its operation. The improved apparatus should also be simple and cheap to produce and thereby be able to present an appealing price to customers.